Datasheet

LTC3838
50
3838fa
TYPICAL APPLICATIONS
Figure 20. 7V to 14V Input, 5V/5A and 3.3V/5A Dual Output, 2MHz, R
SENSE
, Step-Down Converter with EXTV
CC
Tied to 5V Output
LOAD CURRENT (A)
0.01
50
EFFICIENCY (%)
POWER LOSS (W)
80
90
100
0.1 1
3838 F20b
70
60
0
1.5
2.0
2.5
1.0
0.5
FORCED CONTINUOUS MODE
DISCONTINUOUS MODE
V
IN
= 12V
V
OUT
= 5V
EXTV
CC
TIED TO V
OUT
EFFICIENCY
POWER
LOSS
LOAD CURRENT (A)
0.01
50
EFFICIENCY (%)
POWER LOSS (W)
80
90
100
0.1 1
3838 F20c
70
60
0
1.5
2.0
2.5
1.0
0.5
FORCED CONTINUOUS MODE
DISCONTINUOUS MODE
V
IN
= 12V
V
OUT
= 3.3V
EXTV
CC
TIED TO 5V BIAS SUPPLY
EFFICIENCY MEASUREMENTS INCLUDE POWER
FROM THE 5V BIAS SUPPLY
EFFICIENCY
POWER
LOSS
LOAD CURRENT (A)
0.01
50
EFFICIENCY (%)
POWER LOSS (W)
80
90
100
0.1 1
3838 F20d
70
60
0
1.5
2.0
2.5
1.0
0.5
FORCED CONTINUOUS MODE
DISCONTINUOUS MODE
V
IN
= 12V
V
OUT
= 3.3V
EXTV
CC
FLOATING
EFFICIENCY
POWER
LOSS
100k
45.3k
3838 F20a
1nF
0.1µF
L2
0.8µH
C
OUT2
47µF
w2
DB2
V
OUT1
MT2
MB2
LTC3838
2.2
2.2
73.2k
100k
24.9k
18.7k
V
IN
1µF
1nF
4.7µF
0.1µF
0.01µF
47pF
0.01µF
22pF 22pF
330pF 330pF
L1
0.8µH
R
S1
0.008
R
S2
0.008
C
OUT1
47µF
w2
V
OUT1
5V
5A
V
OUT2
3.3V
5A
V
IN
7V TO 14V
10k 10k
SENSE1
–
SENSE1
+
BOOST1
TG1
SW1
SENSE2
+
BOOST2
TG2
SW2
DRV
CC1
INTV
CC
DRV
CC2
EXTV
CC
DB1
SENSE2
–
BG1 BG2
V
FB2
PGND
V
OUTSENSE1
+
V
OUTSENSE1
–
PGOOD1 PGOOD2
TRACK/SS1
ITH1
DTR1
V
RNG1
TRACK/SS2
ITH2
DTR2
PHASMD
MODE/PLLIN
CLKOUT
RUN2
V
RNG2
SGND
RUN1
RT
PGOOD1 PGOOD2
MB1
MT1
1µF
C
IN2
10µF
w3
C
IN1
39µF
+
10
10
10
10
35.7k
C
IN1
: SANYO 16SVP39M
C
IN2
: MURATA GRM32DR61E106K
C
OUT1
, C
OUT2
: TAIYO YUDEN LMK325BJ476MM-T
DB1, DB2: CENTRAL CMDSH-3
L1, L2: COILCRAFT XAL5030-801MEB
MT1, MB1, MT2, MB2: VISHAY SI7114ADN
68pF